/* ── Design tokens ─────────────────────────────────────── */
:root {
  --navy:   #1E3A5F;
  --teal:   #0F766E;
  --blue:   #1D4ED8;
  --green:  #047857;
  --purple: #7C3AED;
  --orange: #C2410C;
  --gray:   #64748B;
  --red:    #DC2626;

  --bg:      #F8FAFC;
  --surface: #FFFFFF;
  --border:  #E2E8F0;
  --text:    #0F172A;
  --muted:   #64748B;
  --sidebar-w: 220px;

  /* Domain colors */
  --d1-c: #1D4ED8; --d1-l: #DBEAFE;
  --d2-c: #047857; --d2-l: #D1FAE5;
  --d3-c: #0F766E; --d3-l: #CCFBF1;
  --d4-c: #7C3AED; --d4-l: #EDE9FE;
  --d5-c: #C2410C; --d5-l: #FFEDD5;
  --d6-c: #64748B; --d6-l: #F1F5F9;

  /* Band colors */
  --ba-c: #1D4ED8; --ba-l: #DBEAFE;
  --bb-c: #047857; --bb-l: #D1FAE5;
  --bc-c: #7C3AED; --bc-l: #EDE9FE;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
       background: var(--bg); color: var(--text); font-size: 14px; height: 100vh; overflow: hidden; }

/* ── Layout ─────────────────────────────────────────────── */
.layout { display: flex; height: 100vh; }

.sidebar {
  width: var(--sidebar-w); background: var(--navy); color: #fff;
  display: flex; flex-direction: column; flex-shrink: 0;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  padding: 20px 16px; border-bottom: 1px solid rgba(255,255,255,.1);
}
.logo-icon { font-size: 28px; }
.logo-text { font-size: 14px; font-weight: 600; line-height: 1.3; }
.logo-text small { font-size: 11px; opacity: .7; font-weight: 400; }

.nav { flex: 1; padding: 12px 8px; display: flex; flex-direction: column; gap: 2px; }
.nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 12px; border-radius: 8px; color: rgba(255,255,255,.75);
  text-decoration: none; font-size: 13px; transition: background .15s, color .15s;
}
.nav-item svg { width: 18px; height: 18px; fill: currentColor; flex-shrink: 0; }
.nav-item:hover { background: rgba(255,255,255,.1); color: #fff; }
.nav-item.active { background: rgba(255,255,255,.18); color: #fff; font-weight: 600; }

.sidebar-footer { padding: 16px; border-top: 1px solid rgba(255,255,255,.1); }
.grade-badge {
  background: rgba(255,255,255,.12); border-radius: 20px;
  padding: 4px 12px; font-size: 12px; text-align: center; color: rgba(255,255,255,.8);
}

.main { flex: 1; display: flex; flex-direction: column; overflow: hidden; }

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; height: 56px; background: var(--surface);
  border-bottom: 1px solid var(--border); flex-shrink: 0;
}
.topbar-title { font-size: 16px; font-weight: 600; color: var(--navy); }

.content { flex: 1; overflow-y: auto; padding: 24px; }

/* ── Buttons ─────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px;
  border-radius: 8px; border: none; cursor: pointer; font-size: 13px;
  font-weight: 500; transition: opacity .15s, transform .1s;
}
.btn:active { transform: scale(.97); }
.btn:hover { opacity: .9; }
.btn-primary   { background: var(--blue);   color: #fff; }
.btn-success   { background: var(--green);  color: #fff; }
.btn-purple    { background: var(--purple); color: #fff; }
.btn-danger    { background: var(--red);    color: #fff; }
.btn-ghost     { background: transparent;   color: var(--muted); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--bg); }
.btn-sm { padding: 5px 10px; font-size: 12px; }
.btn svg { width: 16px; height: 16px; fill: currentColor; }

/* ── Cards / Surfaces ────────────────────────────────────── */
.card {
  background: var(--surface); border-radius: 12px;
  border: 1px solid var(--border); padding: 20px;
}
.card-sm { padding: 14px 16px; }

/* ── Stat cards ──────────────────────────────────────────── */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 24px; }
.stat-card {
  background: var(--surface); border-radius: 12px; border: 1px solid var(--border);
  padding: 18px 20px; display: flex; flex-direction: column; gap: 6px;
}
.stat-label { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .5px; }
.stat-value { font-size: 32px; font-weight: 700; color: var(--navy); line-height: 1; }
.stat-sub   { font-size: 12px; color: var(--muted); }

/* ── Chips ───────────────────────────────────────────────── */
.chip {
  display: inline-block; padding: 2px 8px; border-radius: 20px;
  font-size: 11px; font-weight: 500; white-space: nowrap;
}
.chip-d1 { background: var(--d1-l); color: var(--d1-c); }
.chip-d2 { background: var(--d2-l); color: var(--d2-c); }
.chip-d3 { background: var(--d3-l); color: var(--d3-c); }
.chip-d4 { background: var(--d4-l); color: var(--d4-c); }
.chip-d5 { background: var(--d5-l); color: var(--d5-c); }
.chip-d6 { background: var(--d6-l); color: var(--d6-c); }
.chip-a  { background: var(--ba-l); color: var(--ba-c); }
.chip-b  { background: var(--bb-l); color: var(--bb-c); }
.chip-c  { background: var(--bc-l); color: var(--bc-c); }
.chip-draft     { background: #FEF9C3; color: #854D0E; }
.chip-published { background: #DCFCE7; color: #166534; }

/* ── Stars ───────────────────────────────────────────────── */
.stars { color: #F59E0B; font-size: 13px; }

/* ── Filter bar ──────────────────────────────────────────── */
.filter-bar {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  background: var(--surface); border-radius: 10px; border: 1px solid var(--border);
  padding: 12px 16px; margin-bottom: 16px;
}
.filter-bar select, .filter-bar input {
  border: 1px solid var(--border); border-radius: 6px; padding: 6px 10px;
  font-size: 13px; color: var(--text); background: var(--bg); outline: none;
}
.filter-bar select:focus, .filter-bar input:focus { border-color: var(--blue); }
.filter-sep { width: 1px; height: 20px; background: var(--border); }
.filter-bar input[type=search] { min-width: 200px; }

/* ── Question table ──────────────────────────────────────── */
.q-table { width: 100%; border-collapse: collapse; }
.q-table th {
  text-align: left; padding: 10px 12px; font-size: 11px; font-weight: 600;
  color: var(--muted); text-transform: uppercase; border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
.q-table td { padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
.q-table tr:hover td { background: #F8FAFC; }
.q-content-cell { max-width: 380px; }
.q-content-text {
  overflow: hidden; display: -webkit-box; -webkit-line-clamp: 2;
  -webkit-box-orient: vertical; line-height: 1.5; font-size: 13px;
}
.q-actions { display: flex; gap: 4px; }

/* ── Question card for review ────────────────────────────── */
.review-list { display: flex; flex-direction: column; gap: 12px; }
.review-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 10px;
  overflow: hidden; transition: box-shadow .15s;
}
.review-card:hover { box-shadow: 0 2px 12px rgba(0,0,0,.06); }
.review-card-header {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 14px; background: var(--bg); border-bottom: 1px solid var(--border);
  cursor: pointer;
}
.review-card-header .q-num { font-weight: 700; color: var(--navy); min-width: 28px; }
.review-card-header .q-preview { flex: 1; font-size: 13px; color: var(--text); overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
.review-card-header .chips { display: flex; gap: 4px; flex-shrink: 0; }
.review-card-body { padding: 14px; display: none; }
.review-card.expanded .review-card-body { display: block; }
.review-card.expanded .review-card-header { background: var(--surface); }

/* ── Form elements ───────────────────────────────────────── */
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }
.form-row-3 { grid-template-columns: 1fr 1fr 1fr; }
.form-group { display: flex; flex-direction: column; gap: 4px; }
.form-group label { font-size: 12px; font-weight: 500; color: var(--muted); }
.form-group input, .form-group select, .form-group textarea {
  border: 1px solid var(--border); border-radius: 6px; padding: 7px 10px;
  font-size: 13px; color: var(--text); outline: none; font-family: inherit;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  border-color: var(--blue); box-shadow: 0 0 0 2px rgba(29,78,216,.1);
}
.form-group textarea { resize: vertical; min-height: 80px; }

/* ── Upload zone ─────────────────────────────────────────── */
.upload-zone {
  border: 2px dashed var(--border); border-radius: 12px; padding: 48px 24px;
  text-align: center; cursor: pointer; transition: border-color .2s, background .2s;
  background: var(--surface);
}
.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--blue); background: #EFF6FF;
}
.upload-icon { font-size: 48px; margin-bottom: 12px; }
.upload-title { font-size: 16px; font-weight: 600; color: var(--navy); margin-bottom: 6px; }
.upload-sub   { font-size: 13px; color: var(--muted); }
.upload-zone input[type=file] { display: none; }

/* ── Progress ────────────────────────────────────────────── */
.progress-bar-wrap { background: var(--bg); border-radius: 20px; height: 6px; overflow: hidden; }
.progress-bar { height: 100%; background: var(--blue); border-radius: 20px; transition: width .3s; }
.step-list { display: flex; flex-direction: column; gap: 8px; }
.step-item { display: flex; align-items: center; gap: 10px; padding: 8px 0; font-size: 13px; }
.step-dot { width: 20px; height: 20px; border-radius: 50%; flex-shrink: 0; display: flex; align-items: center; justify-content: center; font-size: 11px; }
.step-dot.done    { background: #DCFCE7; color: var(--green); }
.step-dot.active  { background: var(--d1-l); color: var(--blue); }
.step-dot.pending { background: var(--bg); border: 1px solid var(--border); color: var(--muted); }
.spinner { display: inline-block; width: 14px; height: 14px; border: 2px solid rgba(29,78,216,.3); border-top-color: var(--blue); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Paper builder ───────────────────────────────────────── */
.paper-layout { display: grid; grid-template-columns: 1fr 320px; gap: 16px; }
.basket-panel {
  background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  position: sticky; top: 0; max-height: calc(100vh - 120px); display: flex; flex-direction: column;
}
.basket-header { padding: 14px 16px; border-bottom: 1px solid var(--border); }
.basket-title  { font-weight: 600; color: var(--navy); font-size: 14px; }
.basket-body   { flex: 1; overflow-y: auto; padding: 8px; }
.basket-item {
  display: flex; align-items: flex-start; gap: 8px; padding: 8px;
  border-radius: 8px; background: var(--bg); margin-bottom: 6px; font-size: 12px;
}
.basket-item .bq-content { flex: 1; line-height: 1.4; overflow: hidden; display: -webkit-box;
  -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.basket-footer { padding: 14px 16px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 8px; }

/* ── Modal ───────────────────────────────────────────────── */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,.4);
  z-index: 1000; display: flex; align-items: center; justify-content: center;
}
.modal-box {
  background: var(--surface); border-radius: 14px; padding: 0;
  max-width: 680px; width: 90%; max-height: 85vh; overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0,0,0,.2);
}
.modal-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px; border-bottom: 1px solid var(--border); position: sticky; top: 0;
  background: var(--surface); z-index: 1;
}
.modal-title { font-size: 15px; font-weight: 600; color: var(--navy); }
.modal-close {
  width: 28px; height: 28px; border-radius: 50%; border: none; background: var(--bg);
  cursor: pointer; font-size: 16px; display: flex; align-items: center; justify-content: center;
  color: var(--muted);
}
.modal-close:hover { background: var(--border); }
.modal-body { padding: 20px; }
.modal-footer {
  display: flex; justify-content: flex-end; gap: 8px;
  padding: 14px 20px; border-top: 1px solid var(--border);
  position: sticky; bottom: 0; background: var(--surface);
}

/* ── Toast ───────────────────────────────────────────────── */
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  background: #1E293B; color: #fff; padding: 10px 20px; border-radius: 8px;
  font-size: 13px; z-index: 9999; box-shadow: 0 4px 12px rgba(0,0,0,.2);
}

/* ── Misc ────────────────────────────────────────────────── */
.section-title {
  font-size: 13px; font-weight: 600; color: var(--navy);
  text-transform: uppercase; letter-spacing: .5px; margin-bottom: 12px;
}
.empty-state {
  text-align: center; padding: 60px 20px; color: var(--muted);
}
.empty-state .icon { font-size: 48px; margin-bottom: 12px; }
.empty-state p { font-size: 14px; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.q-count-badge {
  background: var(--blue); color: #fff; border-radius: 20px;
  padding: 2px 8px; font-size: 11px; font-weight: 600;
}
.divider { height: 1px; background: var(--border); margin: 16px 0; }

/* Scrollbar styling */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #CBD5E1; border-radius: 3px; }

/* Table in cards */
.table-wrap { overflow-x: auto; }

/* ── Grade switcher ──────────────────────────────────────── */
.grade-switcher { padding: 8px 12px 4px; border-bottom: 1px solid rgba(255,255,255,.1); }
.grade-switcher-label { font-size: 10px; text-transform: uppercase; letter-spacing: .5px; color: rgba(255,255,255,.5); margin-bottom: 8px; }
.grade-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 4px; }
.grade-btn {
  background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.12);
  color: rgba(255,255,255,.7); border-radius: 6px; padding: 5px 4px;
  font-size: 11px; cursor: pointer; transition: background .15s, color .15s;
  text-align: center;
}
.grade-btn:hover { background: rgba(255,255,255,.18); color: #fff; }
.grade-btn.active {
  background: rgba(255,255,255,.25); color: #fff;
  border-color: rgba(255,255,255,.4); font-weight: 700;
}

/* ── User info in sidebar footer ─────────────────────────── */
.user-info { display: flex; align-items: center; gap: 8px; }
.user-avatar {
  width: 34px; height: 34px; border-radius: 50%;
  background: rgba(255,255,255,.2); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 15px; font-weight: 700; flex-shrink: 0;
}
.user-details { flex: 1; min-width: 0; }
.user-name { font-size: 13px; font-weight: 600; color: #fff; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.user-role { font-size: 11px; color: rgba(255,255,255,.6); }
.logout-btn {
  width: 28px; height: 28px; border-radius: 6px; display: flex; align-items: center;
  justify-content: center; color: rgba(255,255,255,.6); text-decoration: none;
  transition: background .15s, color .15s; flex-shrink: 0;
}
.logout-btn:hover { background: rgba(255,255,255,.15); color: #fff; }
.logout-btn svg { width: 16px; height: 16px; fill: currentColor; }

/* ── Grade badge inline in topbar ────────────────────────── */
.grade-badge-inline {
  background: #EFF6FF; color: var(--blue);
  border: 1px solid #BFDBFE; border-radius: 6px;
  padding: 2px 8px; font-size: 12px; font-weight: 600;
  margin-right: 8px;
}

/* ── Image lightbox ──────────────────────────────────────── */
.img-lightbox {
  position: fixed; inset: 0; background: rgba(0,0,0,.85);
  z-index: 2000; display: none; align-items: center; justify-content: center;
  cursor: pointer;
}
.img-lightbox img { max-width: 90vw; max-height: 90vh; border-radius: 8px; box-shadow: 0 0 40px rgba(0,0,0,.5); }
.lightbox-close {
  position: absolute; top: 16px; right: 20px; background: rgba(255,255,255,.15);
  border: none; color: #fff; font-size: 20px; width: 36px; height: 36px;
  border-radius: 50%; cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: background .15s;
}
.lightbox-close:hover { background: rgba(255,255,255,.3); }

/* ── Question image thumbnail in table ───────────────────── */
.q-thumb {
  width: 36px; height: 36px; object-fit: cover; border-radius: 4px;
  border: 1px solid var(--border); float: left; margin-right: 8px;
  cursor: pointer; flex-shrink: 0;
}

/* ── Stat card icon ──────────────────────────────────────── */
.stat-icon { font-size: 24px; margin-bottom: 4px; }

/* ── Empty state ─────────────────────────────────────────── */
.empty-state .empty-icon { font-size: 48px; margin-bottom: 12px; }

/* ── AI Provider selector ────────────────────────────────── */
.provider-btn {
  flex: 1;
  cursor: pointer;
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  transition: border-color 0.15s, background 0.15s;
  display: block;
}
.provider-btn:hover { border-color: #93C5FD; }
.provider-btn-active { border-color: var(--blue) !important; background: #EFF6FF; }
.provider-btn-inner { display: flex; align-items: center; gap: 10px; }